Recently opened in New York, the High Line is a unique new public park as it isn’t at ground level, but elevated on the former freight railroad spur called the West Side Line. The park covers 2.33 km (1.45 miles) along 10th Avenue from West 30th Street in the North to Gansevoort Street in the South. The original rail line has a long and fascinating history – built in the 1930s to remove rail traffic from the streets, its use declined and was finally closed in 1980, after which it was slowly dismantled by landowners. When plans were…